Apparatus for reproducing rotary motion



July 11, 1939. R. MUNNICH ET AL 2,155,719

APPARATUS FOR REPRODUCING ROTARY MOTION Filed April 2, 1957 Patented July 11, 1939 UNITED STATES PATENT OFFICE APPARATUS FOR REPRODUCING ROTARY MOTION Application April 2, 1937, Serial No. 134,624 In Germany April 6, 1936 3 Claims.

This invention relates to apparatus for reproducing rotary motion.

It is an object of the invention to provide an improved apparatus of the kind described.

To this end, in combination with an electromagnet controlled by impulses which may be transmitted from a distant-control apparatus, a shaft is provided, a pulley on the shaft, an armature connected to the electromagnet, a friction block operatively connected to the armature and arranged to engage the pulley when the armature is attracted, means for holding the friction block away from the pulley when the armature is released, a ratchet wheel connected to the pulley and a spring-controlled pawl for engaging between the teeth of the ratchet wheel.

The friction drive according to the invention is an improvement over the usual pawland ratchet mechanism in that it reduces wear and eliminates noise, and that it can easily be duplicated for operation in opposite directions without requiring an extra pulley. Pawland ratchet means are provided in the present apparatus only for arresting the friction pulley in a definite position after it has been operated by the friction block.

Heretofore, notwithstanding the employment of complicated extra equipment, reproduction of the rotary motion of the distant control for exactly equal angles was impossible without subsequent corrections, nor was it possible to obtain precise synchronisation such as is effected mechanically, for instance, by a flexible shaft. The telephone selector principle can be employed only for the distant control of definite circuits.

The cost of the means employed, however, compares unfavorably with their performance, and it is quite impossible to control from a distance all adjustments on broadcasting apparatus or the like, in which considerations of space and the electric sensitiveness of the apparatus further complicate the conditions. Nor is the telephoneselector with separate contacts for each position a suitable solution on account of the great wear of the contacts. The fine synchronisation necessary owing to transmitter fluctuations is not possible in the fixed condenser groups employed in this instance.

The apparatus according to the present invention is adapted to all requirements and effects an ideal distant control.

The apparatus according to the invention might be termed a flexible shaft of electric character, the employment of which is especially advantageous for apparatus, in which it is desirable that the operator should be at a distance from the apparatus, for instance television apparatus, stage-illumination, for the sound regulation of broadcasting apparatus, and for apparatus in which owing to the presence of the operator .5 disturbing effects occur, for instance ultra short wave receivers, or, measuring apparatus, or in which several apparatus producing noise have to be controlled from a single station, and in which the operators station is sound-insulated, 10 for instance guns, apparatus in laboratories which have to be accommodated so that direct control is impossible, for instance under water,

in vacuo, in gas filled rooms to which access is dangerous, such as Rontgen apparatus, experi- 15 mental fields or the like.

In the accompanying drawing two apparatus embodying the invention are illustrated by way of example.

Fig. 1 is an elevation of an apparatus with 20 two driving mechanisms for alternating rotation of its shaft in opposite directions.

Fig. 2 shows an apparatus equipped for rotation in one direction only, with means for automatically interrupting the circuit of its operat- .25 ing electromagnet after a given number of impulses.

Fig. 3 is a side elevation of the locking pawl for the apparatus in Fig. 1 viewed in the direction of arrow III. 30

Fig. 4 is a detail showing one end of a rocking arm, with its friction block.

Fig. 5 shows the upper portion of the apparatus in Fig. 1.

Referring now to the drawing, it is understood 35 that any suitable means may be provided for transmitting impulses to the operating electromagnets 44 and 44 of the apparatus, but in the present instance it has been assumed that the impulse transmitter is of the kind described in our co -pending application for Impulse transmitter, Ser. No. 134,625, filed April 2, 1937 and the battery M by which the transmitter is supplied with energy, is shown in Fig, 2.

l is a shaft mounted for rotation in a pair of 45 plates 8, Fig. 5, 2 is a ratchet wheel, and 3 is a pulley keyed on the shaft. The operating electromagnet by which the friction drive of the pulley 3 is operated, and the mechanism for actuating the drive, will be described only for the right side of the apparatus by which the shaft 1 is rotated clockwise. The parts at the left are quite similar and are distinguished by the index 44 and 44' are the operating electromagnets to which impulses are transmitted through a circuit 48, 49, 50 the battery 4| being connected to the central wire 48. The armature 5 of the operating magnet 44 is pivoted to one shank of the magnet core. The other shank 23 has a curved recess 24 in which engages the correspondingly curved free end 6 of the armature 5. The armature 5 has a row of holes 25 in one of which a suitable pivot is inserted for connecting to the armature the lower end of a link i Whose upper end is pivotally connected to the outer end of a rocking arm 9 fulcrumed on the plate 8 at 36 outside the axis of the shaft I. Secured to the top of the plates 8 is a yoke H from which the rocking arm 9 is suspended by a spring I9. The rocking arm is held in the substantially horizontal initial position indicated by a thread or loop I5 Whose ends are anchored in a bracket 31. Pivoted to the arm 9 is a friction block it? whose inner end is exchangeably secured in a holder 52 and whose outer end is bevelled for engaging the pulley 3. A spring 33 holds block l3 against a check 4 on arm 9. The block I3 is preferably made of rubber as this material combines great adhesion with a high degree of flexibility and so is able to hug the perimeter of the pulley. It is important that the fulcrum 36 of the rocking arm 9 should be outside the axis of shaft I, as shown, for by these means the end of the block l3 and the perimeter of the pulley 3 move on arcs of circles about centres spaced widely apart, and a sort of camming action is exerted by the block engaging the pulley.

When the operating magnet is excited it attracts its armature 5 and rocks the arm 9 through an angle which is determined by the effective length of the armature, i. e. depends on which hole 25 the pivot connecting the link is inserted in. The motion of the rocking arm is finished when the armature 5 has arrived at the lower end of its stroke, i. e. has been fully attracted.

An exactly similar operation, but with the shaft rotating anti-clockwise, is effected by transmitting impulses to the electromagnet 44 at the right.

When the magnet 44 or 44' is 'de-energized, the spring ID or Ill returns the rocking arm 9 or 9' into its initial position defined by the loop |5 or I5.

When the shaft I is rotated, a roller 5 supported by a rocking pawl I8 is forced over the crest between two gaps against the action of a spring and, under the reaction of the spring, enters that semi-cylindrical gap in the ratchet wheel 2 which is now presented to it. A bracket H, Fig. 3, is secured at the side of the ratchet wheel 2, and a pawl It supports the roller l6 and is urged toward the wheel 2 by a U-shaped spring whose lower end is secured to the bracket. The spring has a straight portion I9 by which it is attached to the bracket I1 and is turned over at 29 to form a sort of cam 2| at its free end by which it bears against the pawl l8. An adjustable check 22 is arranged in the bracket I! for arresting the spring l9 after it has been deflected.

If the link I is connected to the outermost hole 25 in the armature 5, the ratchet wheel 2 is fed for two pitches of its teeth. The roller IS on the pawl I8 is forced out of the first gap, jumps two crests and engages in the third gap. The spring I 9 is deflected against a comparatively slight reaction until the roller I6 ascends a crest and the spring now bears against the check 22 so that its effective length is reduced and the reaction is intensified. At this intensified reaction, the

. enters the next gap under the reaction of spring I 9, but it cannot occur that the roller remains on a crest.

The ratchet Wheel 2 may be exchanged against one having a difierent pitch so that the shaft is turned through a greater or lesser angle for each operation of a magnet 44 or 44, and the effective length of the armature 5 or 5 is adapted to the pitch by inserting the pivot of the link 1 or I in a corresponding hole 25 or 25 in the armature. It may be necessary to vary the diameter of the roller IS in conformity with the pitch of the ratchet wheel 2.

It may be desirable to automatically arrest the apparatus after a given number of impulses. This is effected by an arrangement as shown in Fig. 2. This apparatus has only the operating magnet 44 and so its ratchet disk 20., pulley 3a, and shaft la, are rotated anticlockwise only. A cam plate 26 is secured on the shaft la, and equipped with a cam 38 for operating an interrupter after a given number of impulses. The interrupter includes an electromagnet 3| with an armature 29 pivoted at 35, a spring 39 pulling the armature against the core of the interrupter electromagnet 3|, a check 49 for limiting the downward movement of the armature, and a finger 2T pivoted on the armature 29 at 39 and arranged to be engaged by the cam 38, with a spring 28 for straightening the finger 21.

A wire 42 is connected to the battery 4| and to the Wire 48 of the operating magnet 44. A Wire 43 extends from the battery 4| to the pivot 35 of the armature 29. A contact 32 is arranged in a circuit 46 connected to the operating magnet 44, and a contact member is arranged on the armature 29 for closing the circuit 46 when the armature 29 is in its attracted position. A wire 41 is connected to the operating magnet 44 and a switch 5| is arranged for connecting the wires 42 and 41.

Normally the switch 5| is closed and the impulses transmitted through wires 42 and 48 excite the operating electromagnet 44' so that it attracts its armature 29. When the cam strikes the finger 2'! it pushes the finger aside against the action of the spring 28. If it is desired that the apparatus should be arrested after a given number of impulses the switch 5| is opened. The circuit of the interrupter electromagnet is now broken but the circuit of the operator magnet is still established through 43, 35, 32 and 49 so that the apparatus is operated by current impulses in. the manner described. The spring 39 holds the armature 29 in attracted position notwithstanding the de-energization of the interrupter electromagnet 3| but as the spring is weak and the spring 28 is stronger, the finger and the armature move as a unit when the cam 38 strikes the finger, the circuit 46 is broken at 32, and the impulses from 42, 48 no longer energize the oper ating magnet 44.

Obviously the interrupter which has just been described, might also be combined with an apparatus as shown in Fig. 1, with a pair of operating magnets 44, 44, and a second interrupter magnet with a second cam will be provided in this case for cooperation with the operating magnet 44.

We claim:

1. In an apparatus for reproducing rotary motion, a shaft, a pulley on the shaft, an impulsecontrolled operating electromagnet, an armature connected to the electromagnet, a rocking arm, a friction block pivoted on the arm and arranged to engage the pulley, a check on the arm, a spring for holding the block against the check and away from the pulley, a link connected to the arm at one end, means for connecting the other end of the link to the armature in various positions, for holding the friction block against the pulley when the armature is attracted, a ratchet wheel connected to the pulley, and a springmontrolled pawl for engaging between the teeth of the ratchet wheel.

2. In an apparatus for reproducing rotary motion, a shaft, a pulley on the shaft, an impulsecontrolled operating electromagnet, an armature connected to the electromagnet, a friction block operatively connected to the armature and arranged to engage the pulley when the armature is attracted, means for holding the friction block away from the pulley when the armature is released, a ratchet wheel connected to the pulley, teeth on the pulley defining semicylindrical gaps, a roller for engaging in the gaps, a bracket, a U-shaped spring secured to the bracket at one end and arranged to force the roller into the gaps with its free other end, and an adjustable check for arresting the deflected spring.

3. In an apparatus for reproducing rotary motion, a shaft a pulley on the shaft, an impulsecontrolled operating electromagnet, an armature connected to the electromagnet, a friction block operatively connected to the armature and arranged to engage the pulley when the armature is attracted, means for holding the friction block away from the pulley when the armature is released, a ratchet wheel connected to the pulley, a spring-controlled pawl for engaging between the teeth of the ratchet Wheel, and an interrupter arranged in the circuit of the impulse-controlled electro-magnet and including an interrupter electromagnet, a switch for connecting the circuits of the two electromagnets, a contact in the circuit of the interrupter electromagnet, an armature connected to the interrupter electromagnet, means on the armature for closing the contact in the attracted position of the armature, a spring for moving the armature into the attracted position when the interrupter electromagnet is deenergized, a finger pivoted on the armature, a spring for holding the finger as an extension of the armature, and a cam on the shaft for moving the armature away from its attracted position against the action of the spring by which it is moved into such position.

RICHARD MfTNNICI-I. HERMANN BLECHSCHMIDT. 

